1. You've had the virus for some time and just now had an OB. It's not too common, but it's quite possible.
2. Your boyfriend has genital herpes and is one of the asymptomatic majority. Something approaching 90% of infected people don't know they have it because they don't have symptoms that they recognize as being herpes because they are so mild.
3. Has your genital herpes been typed? About 1/3 of new cases of genital herpes are actually type 1 acquired by having oral sex performed by someone who has had cold sores at some time.
Let me know if you have more questions. I'll try to be quicker responding.